Unclassified white matter disorders: A diagnostic journey requiring close collaboration between clinical and laboratory services.

BACKGROUND: Next generation sequencing studies have revealed an ever-increasing number of causes for genetic disorders of central nervous system white matter. A substantial number of disorders are identifiable from their specific pattern of biochemical and/or imaging findings for which single gene testing may be indicated. Beyond this group, the causes of genetic white matter disorders are unclear and a broader approach to genomic testing is recommended. AIM: This study aimed to identify the genetic causes for a group of individuals with unclassified white matter disorders with suspected genetic aetiology and highlight the investigations required when the initial testing is non-diagnostic. METHODS: Twenty-six individuals from 22 families with unclassified white matter disorders underwent deep phenotyping and genome sequencing performed on trio, or larger, family groups. Functional studies and transcriptomics were used to resolve variants of uncertain significance with potential clinical relevance. RESULTS: Causative or candidate variants were identified in 15/22 (68.2%) families. Six of the 15 implicated genes had been previously associated with white matter disease (COL4A1, NDUFV1, SLC17A5, TUBB4A, BOLA3, DARS2). Patients with variants in the latter two presented with an atypical phenotype. The other nine genes had not been specifically associated with white matter disease at the time of diagnosis and included genes associated with monogenic syndromes, developmental disorders, and developmental and epileptic encephalopathies (STAG2, LSS, FIG4, GLS, PMPCA, SPTBN1, AGO2, SCN2A, SCN8A). Consequently, only 46% of the diagnoses would have been made via a current leukodystrophy gene panel test. DISCUSSION: These results confirm the importance of broad genomic testing for patients with white matter disorders. The high diagnostic yield reflects the integration of deep phenotyping, whole genome sequencing, trio analysis, functional studies, and transcriptomic analyses. CONCLUSIONS: Genetic white matter disorders are genetically and phenotypically heterogeneous. Deep phenotyping together with a range of genomic technologies underpin the identification of causes of unclassified white matter disease. A molecular diagnosis is essential for prognostication, appropriate management, and accurate reproductive counseling.

Risk of Adverse Reactions to Oral Antibiotics Prescribed by Dentists.

Dentists prescribe a large portion of all oral antibiotics, and these are associated with a risk of adverse drug reactions (ADRs). The aim of this study was to quantify the risk of ADRs associated with oral antibiotics commonly prescribed by dentists. NHS Digital Prescribing data and Yellow Card Drug Analysis data for 2010 to 2017 were abstracted to quantify dental antibiotic prescribing in England, and the rate and types of ADRs associated with them. During the period of study, the mean number of actively practicing dentists in England was 23,624. Amoxicillin accounted for 64.8% of dental antibiotic prescribing and had the lowest reported rate of fatal ADRs (0.1/million prescriptions) and overall ADRs (21.5/million prescriptions). Indeed, amoxicillin was respectively 6 and 3 times less likely to cause an ADR than the other penicillins, penicillin V and amoxicillin + clavulanic acid, and appears to be very safe in patients with no history of penicillin allergy. In contrast, clindamycin, which is often used in patients with penicillin allergy, had the highest rate of fatal (2.9/million prescriptions) and overall (337.3/million prescriptions) ADRs, with Clostridiodes (formerly Clostridium) difficile infections pivotal to its ADR profile. Other amoxicillin alternatives, clarithromycin and metronidazole, while significantly worse than amoxicillin, were 3 and nearly 5 times less likely to cause an ADR than clindamycin. Ranked from least to most likely to cause an ADR, antibiotics most commonly prescribed were as follows: amoxicillin < cephalosporins < erythromycin < tetracyclines < azithromycin < metronidazole < amoxicillin + clavulanic acid < clarithromycin < penicillin V < clindamycin. This study confirmed the high level of safety associated with use of amoxicillin by dentists and the significantly worse rates of fatal and nonfatal ADRs associated with other penicillins and alternatives to amoxicillin for those who are penicillin allergic. In particular, clindamycin had the highest rate of fatal and nonfatal ADRs of any of the antibiotics commonly prescribed by dentists.

Severe Leukoencephalopathy with Clinical Recovery Caused by Recessive BOLA3 Mutations.

AIM: To identify the genetic aetiology of a distinct leukoencephalopathy causing acute neurological regression in infancy with apparently complete clinical recovery. METHODS: We performed trio whole genome sequencing (WGS) to determine the genetic basis of the disorder. Mitochondrial function analysis in cultured patient fibroblasts was undertaken to confirm the pathogenicity of candidate variants. RESULTS: The patient presented at 18 months with acute hemiplegia and cognitive regression without obvious trigger. This was followed by clinical recovery over 4 years. MRI at disease onset revealed bilateral T2 hyperintensity involving the periventricular and deep white matter and MR spectroscopy of frontal white matter demonstrated a lactate doublet. Lactate levels and mitochondrial respiratory chain enzyme activity in muscle, liver and fibroblasts were normal. Plasma glycine was elevated. The MRI abnormalities improved. WGS identified compound heterozygous variants in BOLA3: one previously reported (c.136C>T, p.Arg46*) and one novel variant (c.176G>A, p.Cys59Tyr). Analysis of cultured patient fibroblasts demonstrated deficient pyruvate dehydrogenase (PDH) activity and reduced quantity of protein subunits of mitochondrial complexes I and II, consistent with BOLA3 dysfunction. Previously reported cases of multiple mitochondrial dysfunctions syndrome 2 (MMDS2) with hyperglycinaemia caused by BOLA3 mutations have leukodystrophy with severe, progressive neurological and multisystem disease. CONCLUSIONS: We report a novel phenotype for MMDS2 associated with apparently complete clinical recovery and partial resolution of MRI abnormalities. We have identified a novel disease-causing variant in BOLA3 validated by functional cellular studies. Our patient's clinical course broadens the phenotypic spectrum of MMDS2 and highlights the potential for some genetic leukoencephalopathies to spontaneously improve.

Porphyromonas gingivalis is the most abundant species detected in coronary and femoral arteries.

An association between oral bacteria and atherosclerosis has been postulated. A limited number of studies have used 16S RNA gene sequencing-based metagenomics approaches to identify bacteria at the species level from atherosclerotic plaques in arterial walls. The objective of this study was to establish detailed oral microbiome profiles, at both genus and species level, of clinically healthy coronary and femoral artery tissues from patients with atherosclerosis. Tissue specimens were taken from clinically non-atherosclerotic areas of coronary or femoral arteries used for attachment of bypass grafts in 42 patients with atherosclerotic cardiovascular disease. Bacterial DNA was sequenced using the MiSeq platform, and sequence reads were screened in silico for nearly 600 oral species using the HOMINGS ProbeSeq species identification program. The number of sequence reads matched to species or genera were used for statistical analyses. A total of 230 and 118 species were detected in coronary and femoral arteries, respectively. Unidentified species detected by genus-specific probes consisted of 45 and 30 genera in coronary and in femoral artery tissues, respectively. Overall, 245 species belonging to 95 genera were detected in coronary and femoral arteries combined. The most abundant species were Porphyromonas gingivalis, Enterococcus faecalis, and Finegoldia magna based on species probes. Porphyromonas, Escherichia, Staphylococcus, Pseudomonas, and Streptococcus genera represented 88.5% mean relative abundance based on combined species and genus probe detections. Porphyromonas was significantly more abundant than Escherichia (i.e. 46.8% vs. 19.3%; p = 0.0005). This study provides insight into the presence and types of oral microbiome bacterial species found in clinically non-atherosclerotic arteries.

A change in the NICE guidelines on antibiotic prophylaxis.

Since 2008, NICE clinical guidelines have stated: 'Antibiotic prophylaxis against infective endocarditis is not recommended for people undergoing dental procedures'. This put UK guidance at odds with guidance in the rest of the world, where antibiotic prophylaxis is recommended for patients at high-risk of infective endocarditis undergoing invasive dental procedures. Many dentists also felt this wording prohibited the use of antibiotic prophylaxis, regardless of the wishes of the patient or their personal risk of infective endocarditis and made it difficult for them to use their clinical judgment to deliver individualised care in the best interests of their patients. NICE have now changed this guidance to 'Antibiotic prophylaxis against infective endocarditis is not recommended routinely for people undergoing dental procedures.' This article examines the implications of this small but important change.

Intravenous amoxicillin/clavulanate for the prevention of bacteraemia following dental procedures: a randomized clinical trial.

OBJECTIVES: Although controversy exists regarding the efficacy of antibiotic prophylaxis for patients at risk of infective endocarditis, expert committees continue to publish recommendations for antibiotic prophylaxis regimens. This study aimed to evaluate the efficacy of four antimicrobial regimens for the prevention of bacteraemia following dental extractions. METHODS: The study population included 266 adults requiring dental extractions who were randomly assigned to the following five groups: control (no prophylaxis); 1000/200 mg of amoxicillin/clavulanate intravenously; 2 g of amoxicillin by mouth; 600 mg of clindamycin by mouth; and 600 mg of azithromycin by mouth. Venous blood samples were collected from each patient at baseline and at 30 s, 15 min and 1 h after dental extractions. Samples were inoculated into BACTEC Plus culture bottles and processed in the BACTEC 9240. Conventional microbiological techniques were used for subcultures and further identification of the isolated bacteria. The trial was registered at ClinicalTrials.gov with ID number NCT02115776. RESULTS: The incidence of bacteraemia in the control, amoxicillin/clavulanate, amoxicillin, clindamycin and azithromycin groups was: 96%, 0%, 50%, 87% and 81%, respectively, at 30 s; 65%, 0%, 10%, 65% and 49% at 15 min; and 18%, 0%, 4%, 19% and 18% at 1 h. Streptococci were the most frequently identified bacteria. The percentage of positive blood cultures at 30 s post-extraction was lower in the amoxicillin/clavulanate group than in the amoxicillin group (P < 0.001). The incidence of bacteraemia in the clindamycin group was similar to that in the control group. CONCLUSIONS: Bacteraemia following dental extractions was undetectable with amoxicillin/clavulanate prophylaxis. Alternative antimicrobial regimens should be sought for patients allergic to the ß-lactams.

Guidelines on prophylaxis to prevent infective endocarditis.

Infective endocarditis is a devastating disease with high morbidity and mortality. The link to oral bacteria has been known for many decades and has caused ongoing concern for dentists, patients and cardiologists. Since 2008, the UK has been out of step with the rest of the world where antibiotic prophylaxis is recommended for high-risk patients undergoing invasive dental procedures. Recent evidence that identified an increase in endocarditis incidence prompted a guideline review by NICE and the European Society for Cardiology--which produces guidance for the whole of Europe. Despite reviewing the same evidence they reached completely opposing conclusions. The resulting conflict of opinions and guidance is confusing and poses difficulties for dentists, cardiologists and their patients. Recent changes in the law on consent, however, may provide a patient-centred and pragmatic solution to these problems. This Opinion piece examines the evidence and opposing guidance on antibiotic prophylaxis in the context of the recent changes in the law on consent and provides a framework for how patients at risk of endocarditis might be managed in practice.

NICE and antibiotic prophylaxis to prevent endocarditis.

Infective endocarditis is a devastating disease with high morbidity and mortality. The link to oral bacteria has been known for many decades and has caused on going concern for dentists, patients and cardiologists. Good oral hygiene has long been advocated to prevent endocarditis. Before 2008, antibiotic prophylaxis before invasive dental procedures was also an important strategy for preventing infective endocarditis for patients at risk of the disease in the UK, and still is in most other countries of the world. In 2008, however, NICE published new guidance recommending that antibiotic prophylaxis in the UK should cease. At the time this was a highly controversial decision. New data suggests that there has been a significant increase in the incidence of infective endocarditis since the 2008 guidelines. The 2008 guidance is being reviewed and draft new guidance is being put out for public consultation. This article discusses the issues raised by the new data and the questions that should be addressed in the review and public consultation.

Report on World Workshops on Oral Medicine (WWOM) IV and V: research themes and citation impact: WWOM VI steering committee.

The first World Workshop on Oral Medicine (WWOM) was held in 1988. The portfolio has continued to expand in scope and impact over the past 26 years. Five World Workshops were conducted between 1988 and 2010, focusing on creation of systematic reviews in biomedicine and health care of importance to the international oral medicine community. WWOM VI was conducted in April 2014 and further extended this modeling. This most recent Workshop also fostered creation of the inaugural joint meeting between the American Academy of Oral Medicine and the European Association of Oral Medicine, together with The British Society for Oral Medicine and the Oral Medicine Academy of Australasia. The goal of the WWOM portfolio is to strategically enhance international oral medicine research, education, and clinical practice. To this end, this report summarizes subject areas for WWOM IV (2004) and research recommendations for WWOM V (2010), as well as citation metrics relative to publications from these two conferences. The information is designed to provide research and clinical context for key issues in oral medicine as delineated by the WWOM portfolio over the past 10 years, as well as for projected outcomes of WWOM VI over the next 12 months.

Prevalence of oral lesions of autoimmune etiology in patients with primary Sjogren's syndrome.

OBJECTIVE: The primary objective of this study was to determine the prevalence of oral lesions of autoimmune etiology (OLAIE) in a cohort of patients with primary Sjögren's syndrome (pSS). MATERIALS AND METHODS: A multi-center retrospective cohort study was conducted at the oral medicine practices of Carolinas Medical Center (CMC), Baylor College of Dentistry (BCD), and the University of Florida (UF). Each site performed a chart review of patients with well-characterized pSS. Clinical variables such as OLAIE, traumatic lesions, and medical conditions were compiled at each site. The association between clinical variables and the presence of OLAIE was then assessed for significance. RESULTS: We evaluated 155 patients diagnosed with pSS. Nineteen patients with pSS (12.3%) had an OLAIE. CMC reported 11 (21.2%) patients with OLAIE, while BCD and UF reported 4 (7.3%) and 4 (8.3%), respectively. Eleven of the 19 (58%) patients with OLAIE had lichen planus, 6 (32%) had aphthous stomatitis, 1 (5%) had chronic ulcerative stomatitis, and 1 (5%) had lesions of systemic connective tissue disease by immunofluorescence. CONCLUSION: The results of our analysis suggest that patients with pSS have a 12% prevalence of OLAIE with a wide range (7.3-21.2%) found between practices. This difference is likely related to the different screening protocols for oral dryness between sites.

Dental postoperative bleeding complications in patients with suspected and documented liver disease.

OBJECTIVES: The aims of this study were to determine the frequency of bleeding complications following dental procedures in patients with known or suspected chronic liver disease and whether international normalized ratio (INR) determination could aid in predicting bleeding complications in these patients. PATIENTS AND METHOD: We identified 90 patients (mean age: 51 ± 9 years) in this retrospective chart review. Sixty-nine patients had a known history of chronic liver disease and 21 had suspected chronic liver disease. Descriptive statistics were determined. Independent sample t-test and one-way variance test were utilized for continuous variables and chi-square test for dichotomous variables. RESULTS: The mean INR value for all patients was 1.2 ± 0.3. The INR value was significantly associated with the diagnosis of liver cirrhosis, the diagnoses of Hepatitis B and C together, the presence of ascites alone, and the number of clinical signs and symptoms (i.e. ascites, jaundice and encephalopathy) present. Nine patients with INR values between 1.5 and 2 underwent invasive dental procedures without postoperative bleeding complications. CONCLUSION: There were no episodes of postoperative bleeding in patients. The findings suggest that clinicians should not rely solely on an INR value to predict post-procedure bleeding in patients with liver disease.

Local drug delivery for oral mucosal diseases: challenges and opportunities.

There are few topical formulations used for oral medicine applications most of which have been developed for the management of dermatological conditions. As such, numerous obstacles are faced when utilizing these preparations in the oral cavity, namely enzymatic degradation, taste, limited surface area, poor tissue penetration and accidental swallowing. In this review, we discuss common mucosal diseases such as oral cancer, mucositis, vesiculo-erosive conditions, infections, neuropathic pain and salivary dysfunction, which could benefit from topical delivery systems designed specifically for the oral mucosa, which are capable of sustained release. Each condition requires distinct penetration and drug retention profiles in order to optimize treatment and minimize side effects. Local drug delivery may provide a more targeted and efficient drug-delivery option than systemic delivery for diseases of the oral mucosa. We identify those mucosal diseases currently being treated, the challenges that must be overcome and the potential of novel therapies. Novel biological therapies such as macromolecular biological drugs, peptides and gene therapy may be of value in the treatment of many chronic oral conditions and thus in oral medicine if their delivery can be optimized.

Implementation of ironXS: a study of the acceptability and feasibility of genetic screening for hereditary hemochromatosis in high schools.

Hereditary hemochromatosis (HH), most often due to HFE C282Y homozygosity, is an iron overload disorder that can result in severe morbidity including hepatic cirrhosis. Predisposition to HH is easily diagnosed and morbidity is preventable by maintaining normal body iron and thus calls have been made to introduce community screening. The current study has been designed to assess the acceptability and feasibility of HH screening in high schools. Students (mostly 15-16 years of age) watched a purpose-designed DVD for education about HH. Those with parental consent were then offered cheek-brush screening for C282Y. Students completed a questionnaire prior to screening. The program was offered to 9187 students at 32 schools and 3489 (38%) had screening. Nineteen C282Y homozygotes (1 in 183) and 376 heterozygotes (1 in 9.3) were identified. More than 90% of students answered each of five knowledge questions correctly. Eight homozygotes (42%) had elevated transferrin saturation, but only two (10.5%) had marginally elevated serum ferritin (SF). We have shown that genetic screening for HH can successfully be offered in the high school setting. Ongoing research in this study will answer questions about the impact of high school students learning that they are at risk of HH.

Incidence of acute oral sequelae in pediatric patients undergoing chemotherapy.

PURPOSE: The purpose of this literature review was to assess the incidence of acute oral sequelae in children receiving cytotoxic therapy. METHODS: The dental literature was searched using 3 electronic databases--Cochrane, Medline, and Embase--from 1966 to 2006 and was limited to articles reporting acute oral sequelae in patients receiving chemotherapy with or without radiotherapy and to individuals younger than 20 years old. RESULTS: Nineteen articles fulfilled the inclusion criteria and were included in this review. The overall incidence of acute oral sequelae in children was 54%. The incidence of oral sequelae was higher in children who received myeloablative therapy prior to bone marrow transplantation compared to those who received only chemotherapy with or without radiotherapy. CONCLUSIONS: The lock of consensus on what constitutes acute oral sequelae and on universally accepted assessment tools complicates the determination of incidence. Acute oral sequelae are frequent in children and the incidence appears to be comparable to adults.

Mutant torsinA interacts with tyrosine hydroxylase in cultured cells.

A specific mutation (DeltaE302/303) in the torsinA gene underlies most cases of dominantly inherited early-onset torsion dystonia. This mutation causes the protein to aggregate and form intracellular inclusion bodies in cultured cells and animal models. Co-expression of the wildtype and mutant proteins resulted in the redistribution of the wildtype protein from the endoplasmic reticulum to inclusion bodies in cultured HEK293 cells, and this was associated with increased interaction between the two proteins. Expression of DeltaE302/303 but not wildtype torsinA in primary postnatal midbrain neurons resulted in the formation of intracellular inclusion bodies, predominantly in dopaminergic neurons. Tyrosine hydroxylase was sequestered in these inclusions and this process was mediated by increased protein-protein interaction between mutant torsinA and tyrosine hydroxylase. Analysis in an inducible neuroblastoma cell culture model demonstrated altered tyrosine hydroxylase activity in the presence of the mutant but not wildtype torsinA protein. Our results suggest that the interaction of tyrosine hydroxylase and mutant torsinA may contribute to the phenotype and reported dopaminergic dysfunction in torsinA-mediated dystonia.